The propulsion and steering of water craft by means of a large number of hydraulic jets is well known, and is shown for instance in U.S. Pat. No. 243,656, issued in 1881 to Stuckey, and No. 3,779,119, issued in 1973 to Mayer. However, such systems are not believed to have gone into general use, in part because they require the complete redesign of the interior of the water craft.